AgentPay

Most agent-payment tools are a wallet — they move money. AgentPay is the layer that decides whether to spend it at all.

AgentPay is the economic intelligence layer for MCP servers and AI agents.

Agents spend money. Most don't know how much, or why, until the session ends and the bill arrives.

AgentPay gives agents economic intelligence — the ability to reason about cost while they work, not after.

It starts with a budget. Every session opens with a hard cap enforced at the payment layer — not in code a model can ignore, but at the point where money moves. The agent knows from the first call exactly what it has to spend.

Before calling a tool, it knows what that call costs. Mid-task, it can check what's left and route to a cheaper alternative if the math doesn't work. When the session ends, a receipt captures every call, every cost, every decision — not a debug log, but proof of economic accountability.

The developer sees all of it: spending patterns per agent, anomaly flags when something loops or spikes, policy controls that enforce exactly which tools an agent can use and how much it can spend on each.

The result is an agent that doesn't just have a budget. It knows how to use one.

Start free: 20 tools (17 free), no USDC needed, no wallet setup required.
Live gateway: https://agentpay.tools

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Install

pip install agentpay-x402            # core (Stellar)
pip install "agentpay-x402[base]"    # + pay tools that settle on Base

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Quickstart — 3 lines, zero setup

17 free tools. No USDC, no wallet, no API keys, no human. quickstart() registers an agent, mints a wallet, and returns a ready, budget-capped session.

from agentpay import quickstart

s = quickstart()                                   # registers + mints a wallet
print(s.call("token_price", {"symbol": "ETH"})["result"]["price_usd"])
print(s.spending_summary())                        # receipt: every call, cost, tx

Set a hard budget, or bring your own funded wallet to pay for tools:

s = quickstart(max_spend="0.50")                   # cap this run at $0.50
s = quickstart(secret_key="S...", base_key="0x...")  # your wallet (Stellar + Base)

Every call is session-tracked, and the cap is enforced before any payment is signed.

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19 Tools (17 Free + 2 Paid)

Every call is session-tracked — you get a receipt showing every tool called, every cost, and every timestamp.

Tool	Parameters	Returns
url_reader	url	Clean markdown content of any web page
web_search	query	Top 5 results with full content
market_snapshot	—	S&P 500, Treasury yield, BTC, ETH, gas in one call
token_price	symbol (BTC, ETH, SOL…)	price_usd, change_24h_pct, market_cap_usd
gas_tracker	—	slow/standard/fast gwei, base_fee_gwei
fear_greed_index	limit (days of history, default 1)	value 0–100, value_classification, history[]
token_market_data	token_a, token_b	volume_24h_usd, market_cap_usd, price_usd
wallet_balance	address, chain (ethereum/stellar)	token balances
whale_activity	token, min_usd (default 100k)	large_transfers[] with direction, total_volume_usd
defi_tvl	protocol (optional, e.g. "uniswap")	tvl, change_1d, change_7d, chains[]
token_security	contract_address, chain	risk_level, is_honeypot, buy_tax, sell_tax
open_interest	symbol (BTC, ETH…)	total_oi_usd, oi_change_1h/24h_pct, long_short_ratio
orderbook_depth	symbol (e.g. ETHUSDT)	best_bid/ask, spread_pct, slippage at $10k/$50k/$250k
funding_rates	asset (optional)	funding_rate_pct, annualized_rate_pct, sentiment per exchange
crypto_news	currencies (e.g. "ETH,BTC"), filter	headlines[] with title, url, sentiment, score
yield_scanner	token, chain (optional), min_tvl	top 10 pools by APY with protocol, tvl_usd, risk_level
dune_query	query_id, limit, fast_only	rows[], columns[], row_count from Dune Analytics
session_create	agent_address, max_spend, label	session_id, budget config, gateway_url, receipt — $0.01
pre_trade_check	symbol, size_usd, side, token_address?	one-call trade verdict (ok/caution/avoid): slippage at YOUR size, side-aware funding carry, OI crowding, optional security — $0.01

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Session Intelligence

This is the economic intelligence layer in practice. The Session gives your agent — and you — real visibility into what happened, what it cost, and why.

from agentpay import quickstart, BudgetExceeded

# quickstart() registers + mints a wallet; the returned session is also a
# context manager, so you can `with` it for a printed receipt on exit.
# Budget caps are exact: max_spend=0.10 (float) == "0.10" (str).
with quickstart(max_spend=0.10) as session:

    # Price an entire multi-tool plan BEFORE spending anything (free, no wallet)
    plan = session.estimate_plan(["token_price", "pre_trade_check", "session_create"])
    plan["total_usdc"], plan["fits_budget"]   # per-step costs + cheaper alternatives inside

    # Reason about cost before committing (use the *_usd Decimals for comparisons)
    if session.would_exceed(session.tool_cost_usd("dune_query")):
        alt = session.suggest_cheaper("dune_query")   # {"name": ..., "price": ...}

    # Call a tool — budget enforced before any payment is signed
    r = session.call("token_price", {"symbol": "ETH"})
    r.data["price_usd"]    # inner tool output  (r["result"]["price_usd"] still works)
    r.cost                 # payment amount, e.g. "0"
    r.network              # settlement chain, e.g. "stellar-mainnet" / "base"

    session.remaining_usd()   # Decimal('0.10')

    # For an external x402 tool that offers several chains, pick one:
    # session.call("https://some-x402-tool/endpoint", {}, chain="base")

    # Full receipt — every call, cost, tx hash, and settlement chain
    print(session.spending_summary())
    # {
    #   "calls": 1, "spent": "$0", "remaining": "$0.1", "budget": "$0.1",
    #   "breakdown": [
    #     {"tool": "token_price", "cost": "Free", "tx_hash": "", "network": "stellar-mainnet"}
    #   ]
    # }

Policy parameters

Control exactly what your agent is allowed to do:

from agentpay import AgentWallet, Session

wallet = AgentWallet(secret_key="S...", network="mainnet")   # or quickstart()'s minted wallet
with Session(wallet,
             gateway_url="https://agentpay.tools",
             max_spend=0.10,
             allowed_tools=["token_price", "gas_tracker", "web_search"],
             max_per_tool={"dune_query": 0.02},
             rate_limit=10,                # max 10 calls/min
             prefer_chain="base") as session:   # Base is the default; pass "stellar" to override
    ...

BudgetExceeded fires before any payment goes out if a tool would push you over the cap, isn't on the allowlist, or exceeds its per-tool limit.

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Example: Market intelligence agent

Five free tools, one session, full receipt.

from agentpay import quickstart

with quickstart() as session:

    snapshot = session.call("market_snapshot", {})
    rates    = session.call("funding_rates",    {"asset": "ETH"})
    oi       = session.call("open_interest",    {"symbol": "ETH"})
    fg       = session.call("fear_greed_index", {})
    whales   = session.call("whale_activity",   {"token": "ETH", "min_usd": 500_000})

    m = snapshot["result"]
    print(f"S&P:       {m['sp500_price']:,.0f}  ({m['sp500_change_pct']:+.2f}%)")
    print(f"ETH:       ${m['eth_price_usd']:,.0f}")
    print(f"Gas:       {m['gas_standard_gwei']} gwei")

    avg_rate = sum(e["funding_rate_pct"] for e in rates["result"]["rates"]) / len(rates["result"]["rates"])
    print(f"Funding:   {avg_rate:+.4f}%/8h")
    print(f"OI 24h:    {oi['result']['oi_change_24h_pct']:+.2f}%")
    print(f"Sentiment: {fg['result']['value_classification']}")
    print(f"Whale vol: ${whales['result']['total_volume_usd']:,.0f}")

    print(session.spending_summary())

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Use it in your agent

Claude Code plugin (one command)

/plugin marketplace add romudille-bit/agentpay
/plugin install agentpay@agentpay

Installs the agentpay-route skill — your agent finds, judges, and pays for the best paid x402 tool within a budget — plus the 17 free tools. No keys needed to route.

MCP server (any runtime)

Self-contained — pure Node, no Python, no repo, no keys to start:

npx -y @romudille/agentpay-mcp

{
  "mcpServers": {
    "agentpay": {
      "command": "npx",
      "args": ["-y", "@romudille/agentpay-mcp"]
    }
  }
}

Exposes the 17 free tools plus verified_route (buyer-side trust oracle — free preview keyless, full paid payload in wallet mode), route (legacy alias) and estimate_plan (price a multi-tool plan before spending). Listed on Glama.

Wallet mode (v2.4.0): add an EVM key and paid tools settle in-place — gasless EIP-3009 on Base (no ETH needed; nothing broadcast client-side, a rejected call moves no USDC) under a hard session cap:

{
  "mcpServers": {
    "agentpay": {
      "command": "npx",
      "args": ["-y", "@romudille/agentpay-mcp"],
      "env": {
        "AGENTPAY_BASE_KEY": "0x<EVM private key>",
        "AGENTPAY_MAX_SPEND": "0.10"
      }
    }
  }
}

Fund the key's address with USDC on Base mainnet; every paid call counts against AGENTPAY_MAX_SPEND and is refused past the cap — the budget story, enforced inside the MCP itself. Use a dedicated small-balance key.

Buyer-side routing — find & pay for the best tool, within a budget

When an agent needs a paid tool, AgentPay discovers the options across the x402 marketplace, drops the fake/empty stubs, ranks by real usage (not price), and recommends the cheapest one that actually works — within a budget. The agent pays the provider directly (peer-to-peer, no custody) and keeps a verifiable receipt.

agentpay-route "funding rates" --budget 0.01   # ranked candidates + a recommendation

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Paid tools: session_create, pre_trade_check, verified_route ($0.01 each)

Three tools cost money today. session_create opens a budget-capped session with a hard max_spend limit — for autonomous agents that need spend enforcement across multiple calls. pre_trade_check is the first outcome bundle: one call returns an ok/caution/avoid trade verdict from live orderbook slippage at your size, side-aware funding carry, open-interest crowding, and an optional contract security scan — with the per-factor breakdown and raw components embedded. verified_route is the buyer-side trust oracle: "I need X, budget $Y — which x402 tool is real?" It sweeps the whole marketplace, collapses sybil/factory clusters, keeps only providers relevant to your need, ranks them by real unique-payer usage × the Prober's paid delivery scores, and returns one vetted recommendation with a ready-to-pay challenge. All 17 data tools remain free.

Price any plan before spending a cent (free, no wallet): POST /v1/plan/estimate, or session.estimate_plan([...]) from the SDK.

When metered inference ships, it works through the same Session interface — your agent checks cost, decides if it's worth it, and pays in USDC on Stellar or Base.

# Future — inference as a Session tool
remaining = session.remaining()
infer_cost = session.tool_cost("inference")   # e.g. "$0.02"

if remaining >= infer_cost:
    result = session.call("inference", {"prompt": "...", "model": "claude-haiku"})
else:
    result = session.call("url_reader", {"url": summary_url})  # cheaper path

To fund a wallet for session_create: send USDC to a Stellar wallet (S... key, issuer GA5ZSEJYB37JRC5AVCIA5MOP4RHTM335X2KGX3IHOJAPP5RE34K4KZVN) or a Base wallet (0x..., contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913).

Eating our own dog food

AgentPay's flagship analyst agent (agents/analyst/) runs daily on these exact rails as a real customer: it prices its plan with estimate_plan, gathers free intel, buys pre_trade_check verdicts on the majors under a hard $0.25 cap, and publishes a market note with an on-chain-verifiable receipt. The first best customer is the house.

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Architecture

AgentPay is an x402 payment gateway and economic intelligence layer — agents call tools within a hard budget cap, pay USDC on-chain when tools cost money, and accumulate a full session receipt as they work. Free tools skip the payment step entirely; the session tracking and cost awareness are always on.

agent (Python SDK)
    │
    │  POST /tools/{name}/call
    │  ← 200 {result: ...}              ← free tools return directly
    │  ← 402 {payment_id, amount, ...}  ← paid tools (session_create, pre_trade_check)
    │  → USDC on Stellar (~3–5s) or Base (~2s)
    │  → retry with X-Payment header
    │  ← 200 {result: ...}
    ▼
gateway (FastAPI on Railway)
    │
    ├── registry/registry.py   — 19-tool catalog (17 free; session_create + pre_trade_check, $0.01 each)
    ├── gateway/routes/plan.py — POST /v1/plan/estimate (free pre-flight plan pricing)
    ├── gateway/radar.py       — Arbitrum x402 Radar discovery + settlement verify (see RADAR.md)
    ├── gateway/stellar.py     — Stellar payment verification via Horizon
    ├── gateway/base.py        — Base payment verification via JSON-RPC
    └── gateway/services/tools_runtime.py — real API dispatchers
            ├── Jina Reader       url_reader
            ├── Jina Search       web_search
            ├── Yahoo+CoinGecko   market_snapshot
            ├── CoinGecko         token_price, token_market_data
            ├── Etherscan V2      gas_tracker, whale_activity, wallet_balance
            ├── DeFiLlama         defi_tvl, yield_scanner
            ├── alternative.me    fear_greed_index
            ├── Reddit            crypto_news
            ├── Dune Analytics    dune_query
            ├── GoPlus            token_security
            └── Binance+Bybit+OKX funding_rates, open_interest, orderbook_depth

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Discovery

Directory	Status
PyPI	✅ agentpay-x402
x402scout	✅ indexed, health-checked every 15min
Glama MCP	✅ listed
awesome-x402	✅ listed
npm	✅ @romudille/agentpay-mcp
402index.io	✅ domain verified, 17 tools synced
Coinbase Bazaar	✅ indexed (session_create, Base)
Claude Code plugin	✅ /plugin marketplace add romudille-bit/agentpay
xpay.tools	🔜 submission in progress

Agent-readable endpoints:

Endpoint	Purpose
/.well-known/agentpay.json	AgentPay manifest
/.well-known/agent.json	A2A agent card
/llms.txt	LLM-readable service description
/.well-known/l402-services	402index.io discovery format